Method of and apparatus for forming flanged casing bottom



April 25, G. A. LYON METHOD OF AND APPARATUS FOR FORMING FLANGED CASINGBOTTOM Filed Aug. 10, 1956 4 Sheets-Sheet 1 L z E 17in Z George A/berfLyon April 25, 1961 G. A. LYON 2,980,993

METHOD OF AND APPARATUS FOR FORMING FLANGED CASING BOTTOM Filed Aug. 10,1956 4 Sheets-Sheet 2 F qa5 2 L12 fizz-1T George /L/ber1 L 1 1011ZZZ/"E22 UT George l klber 011 April 25, 1961 G. A. LYON 2,980,993

METHOD OF AND APPARATUS FOR FORMING FLANGED CASING BOTTOM Filed Aug. 10,1956 FJ HZU 4 Sheets-Sheet 4 be 275:7? George A/berf [.5012

r 2,980,993 '7 i. v F AND APPARATUS FOR FORMING FLANGED CASING BO'I'IOMI George Albert Lyon, 13881 W. Chicago Blvd,

.7 f Detroit 28,Mich,

. 1 Filed Aug. 10,1956; Ser. No. 603,326 I s .(cn. 29 -534 mrnon Thisinvention relates to a method of and apparatus for forming casings andmore particularly to a method of forming the bottom of the casing andproviding it with a flange or skirt beyond the normal confines of thecasing. Y

a This invention comprises a continuation-in-partof the sub ect matterof my pending application, Serial No. 260,673, filed December 8, 1951,now Patent No. 2,805,- 466, and also relates to an improvement on thedisclosure ofmy issued patent, No, 2,360,354, issued October 17,1944.

{An object of this invention is to provide an improved method of andapparatus for forming the bottom of the casing and of providing suchbottom with an annular I flange or skirt extending beyond the normalconfines from metal displaced radially during the forming of the bottom.

1 My invention advantageously lends itself for use with cold working andcoining processes, but may be used equally as well inother processes,such as in hot forgmg. I j v j t will be appreciated, however, that inthe forming of casings or vessels for use in ammunition, it is importantthat the grain structure of the metal be properly oriented at the bottomof the casing so as to preclude fractures from occurring between thewall of the casing and its bottom during the use of the same. v

The present invention provides an improved method of so forming thebottom of the casing that excess metal can be effectively displacedradially for use as a flange without disturbing the grain structure ofthe metal at the bottom of the casing.

According to the general features of this invention, there is providedin a method of forming the bottom E 2,980,993 Patented Apr. 2 5., 196lice of the forming member, said plunger being adapted to presslongitudinally downwardly from within the casing against the insidesurface of the bottom while the bottom is backed up by the lower diemember to displace metal from the bottom radially outwardly into athickened bottom margin at its junction with the easing wall saidforming head of reduced diameter being cooperable with the plunger inassisting in the displacement of the thickened margin beyond theexterior confines of the casing wall in the formation of a thickenedannular rib, said flared wiping portion and said forming head beingrelatively movable with respect to one another so the wiping portion ispassed over the thickened annular rib and the forming head forprogressively elongating said obliquely inclined rib in an axialdirection to form it into an annular skirt depending down= wardly fromsaid casing bottom in longitudinal alignment with the casing wall.

Other features of the invention relate to the provision of a novel dieapparatus for effectively forming the displaced annular metal beyond theconfines of the easing into the desired flange or skirt. c Otherobjects, features and advantages of the present invention will bereadily apparent from the following detailed description of certainpreferred embodiments thereof, taken in conjunction with theaccompanying drawings, in which; V Y

Figure l is an edge elevational view of a metal blank suitable fordrawing a shell casing;

Figure 2 is a vertical sectional view of a casing cup following thefirst draw of the blank of Figure 1; v

i Figures 3 andi4 are longitudinal sectional views showing twoconsecutive further draws 'of the casing;

. .Figure 5 is a. fragmentary view partly in section similar, to Figure4 butillustrating diagrammatically how a punch travelsdownwardly withinthe confines of the casing wall to act against the curved bottom of theeasof a casing having an annular wall the steps of ex- I ternallybacking up the periphery of the curved surface Ofthe bottom, internallypressing against the curved surface vof said bottom whileipressurerelieving a gen: erally central area of the curved surface to flow themetal thereof axially away from the bottom and radially bottom, andwiping said rib to form an'annular skirt by radially inwardly displacingand axially outwardly elongating said rib thereby concentricallyaligning the radial surface of the annular skirt with said annular wall.

; ,According to still further features of the present i i-v ventionthere is provided an apparatus for forming a bottom of a casing having acylindrical wall, means including a plunger and a forming member aboutthe plunger having a flared wiping portion with said plunger and saidforming member being movable with'respect r Figure 7 is a fragmentarycross-sectional view similar to, Figure 6 showing diagrammatically afurther step comprising moving the lower die member upwardly to thickenthe center of the bottom and to further thin out the bottom wall so asto displace metal radially outwardly into an outwardly projectingannular bulge or rib;

Figure 8 is a fragmentary cross-sectional view diagrammatically showinghow a punch and die can cooperate in flattening out the bottom of thecasing as formed in Figures 6 and 7 so as to provide the casing bottomwith a radially, projecting flange; I Figure 9 is a fragmentarycross-sectional illustrating the" completed casing similar to that shownin Figure 6 of my aforesaid co-pending application; and

' Figure 10 is a fragmentary cross-sectional view illustratingdiagrammatically a modification of the invention wherein after thecasing bottom is formed as shown in Figure 7, it is acted upon by awiping annular die to deflect the annular bulge downwardy into adepending skirt aligned with the wall of the casing.

As shown on the drawings: The method of the'prese'nt invention will bebest understood in connection with a description of the several viewsshown in. the drawings. v A

In drawing a metal shell casing according to the pres,- ent invention, ametalblank 25 may be initially coined or used directly as a cut blank,depending'on the final shape of head desired. Preferably, the blank 25is circular. 'lfdesird, it may be initially formed with a centralconcave-convex depression or embossment 27 which will serve as centeringmeans when placing the blank into a drawing die. i The blank er Figurelis subjectedto-successive draws to progressively shape it into anelongated closed end tube or case as represented in Figures 2, 3'and 4,showing successive states of elongationof the casing. I Figure 2 depictsthe first draw or cupping ofthe case, generally identified at'28. Inthis operation, the marginal portion of the blank 25 is turned axiallyand provides a tubular side wall 29. One endof the case is closed by awall 30 providing a base or 'head, thecasebeing open at theopposite end.The base wall 30'remains of substantially the same thickness as-at theconclusion of the initial coining, while the marginal portion of theoriginal blank is worked substantially thinner to afford the necessaryelongation in the side wall 29. In the present instance, the base wall30 is preferably concave-convex.

According to the present invention, the drawing of the case '28 isstopped short of the open endof the casing. Asa result, a bead or collar31 of the material of the side wall remains at the mouthof the cupfollowing the first draw as shown in Figure 2. This collar 31'isretained in each of the succeeding draws, which may be two additionaldraws, as shown respectively in Figures Sand 4, by which the cup ofFigure 2 is substantially elongated'to the ultimate length of casingdesired, as'shown in Figure 4. It will be observed that throughout thedrawing, the side wall 29 becomes successively thinner while the bottomwall 30 remains of substantially the same thickness 1 and the mouth andcollar 31 remains of substantially the same thickness or mass ofmaterial. To accomm'o'date the drawing die mechanism the collar 31flares radially outwardly.

The specific method and "apparatus for forming the flaring collar isdisclosed and claimed in my aforesaid co-pending application and doesnot, per se, constitute a part of the present invention. However, byvirtue of the fact that the casing wall 29 has an'outward bulge orcollar 31 at its upper end, it is not feasible in the further forming ofthe bottom in the die structure to come downwardly over the casing wallby an annular die member. s

Therefore-in accordance with the spirit of this invention, I propose toprovide a method of and apparatus for forming whereby a punch canannularly travel inside of the wall 29 for performing preliminary metaldisplacementoperations'on the casing bottom 30 as shownin Figure 6 andadditional die apparatus can be moved upwardly from the bottom of thecasing to continue the forming of thebottom and the required annularflange'or skirt thereon as shown in Figure 7.

I desire it understood, however, that the invention hereof is notnecessarily limited to the particular" shape of casing shown in myco-pending application, but can be used equally as well to provideflanges or skirts of different shapes, one of which is shown' in Figure10 as'I shall describe more'fully hereinafter.

Before (proceeding with the description, I also desire to call attentionto the fact that the die structure is more or less purposely illustrateddiagrammatically in the accompanying drawings since any suitable pressequipment and dies may be employed for working and deflecting the metalin the manner shown. Particularly good-results can be obtained by thecold working and-coiningof the casing or vessel from: cold rolled-steel.

Proceedingfurther with the description, it will now be observed fromFigures 5 aud o the casing 28 is further processedin accordancewiththisirivention. "At the conclusionof the drawing of the casing 28, thecollar 31 is swage'd "radially inwardly and preferably uniformly 'toshown inFigure5, is' cylindrical. This still leaves asubstantialthickness of material projecting uniformly radially about the mouthportion of the casing, affording an annular flange of substantial mass.The collar 31 can be machined as desired, fonexample, by squaring off ashoulder '32 (Figure 9,) on the lower end o f the collar 31 and bymachining a'rabbet'groove 33 in the inner side of the collar.

As *is shown in Figure 5, the'casing '28 'is set upon a lower die member34'having a'dished or head surface 35 to mate'with the'botto'mwall orthe'curved base wall 30. Disposed around the casing 28 is a ring orforming member 36. Punch or plunger die member 37 is then urgeddownwardly into the interior of the casing 28 after the ring and lower'die have been placed inposition;

' The punch 37 has'a curved or rounded annular bottom portion 38-whichis'adapted to mate with a portion of the inner curved-surface of thebase'wall 30. Centrally of the bottom portion 38 the punch 37 isflattenedat-39 and hasa central recess 40. The punch 37 is shown inpreliminary engagement with the base wall 30 in Figu're'b.

\Vhen the'punch 37 is forced or urged against the base wall'30 backed upby the lower die 34 the base wall '30 is intermediately or centrallythickened at 41 (Figure'7) and the bottom wall 30 about the thickenedportion 41- is thinned at 42so as to displace metal'radially outwardlyinto anoutwardly projecting annular bulge or rib 43.

To facilitate formingof the rib 43 the ring 36 has a downwardly andoutwardly flared portion 44 and the lower diemember 34 has a reducedshank 45 of asmaller diameter than the die member 34. The shank has-anoutside annular surface 46 which is angled toward the central'axis ofthe casing 28 (Figures 6" and 7).

Figure 8 illustrates diagrammatically 'how' a punch 47 and a die 48 cancooperate in flattening out the bottom of the casing as formed in Figure6 and 7 so'asto' provide thecasing bottom with a radially projectingflange 43. To this end, it will be noted, the punch 47 has'an flattenedbase portion 49 and a central recess 50 with-a flattened bottom 51. Thelower diemember 48 is illustrated as being flattened so that it cancooperate with thepunch 47 in flattening out the bottom casing wall 30.

Figure 9 illustrates the completed casing 28 after the bottom wall 30has been flattened and provided with=a central bore therein.

Figure l0 shows a modification of the present invention wherein afterthe casing bottom is formed asjsho wn in Figure 7, the'same' referencenumerals being 'againused where" pertinent, it is acted upon bytheannul'ar wiping die or ring member 36 to 'deflect theannular biilge-43f(as shown in'Figure '7) a"downwardly elongateddepending skirt 55the "out'sidesurface'of which is alignedwi'ththe wall of the casing. I Iv The utilization'of the wiping die 36in the novel manner here'employedis particularly advantageous since the-wiping die may"move" freely ofthe collar'31. In themovement of the wiping'die or'ring'36, the flaredportion '44of the ring 36 cooperates with the reduced s'hank45'onthelower die member 34 i in deflecting the bulge 'into' thedepending'skirt' 55. I

The"casirig"des'c'ribed herein'may be made 'from'any suitable materialsuch as steel of any appropriate grade or composition for the purposeintended. On the other hand; the cas'ihgs' may be made from'br'ass orother-"metal or alloy. 7 V, I

Where "steel is used; sph'eroidizing may be resorted to if necessary,-but-under appropriate circumstances the formation of the casings bycoining and subsequ'ent dr'awing'may be accomplished without thespheroidizing treatment.

Between-the various working-steps on the several" casings,-suitable=heat treatment may be employed as-desired,

such as annealing, normalizing and hardening.

assumes may be effected without departing from the scope of the novelconcepts of the present invention.

1 claim as my invention:

1. A method of drawing metallic type casings, comprising initiallycupping a metal blank from an at least marginally flat condition into anelongated tubular walled shell to a point short of the marginalextremity of the blank but turning said marginal extremity into aflaring mouthed undrawn collar, then drawing the tubular wall of thecupped blank to elongate the casing while maintaining said undrawnmargin collar in the substantially original thickness of the same asturned into said flaring mouthed condition, thereafter substantiallystraightening said flaring mouthed collar longitudinally of saidelongated tubular wall, pressing longitudinally downwardly from Withinthe casing against the inside curved surface of the curved bottom,internally backing up the periphery of the internal curved surface ofthe curved bottom while pressing upwardly against the curved bottom fromthe exterior thereof and pressure relieving the internal central area ofthe curved surface to simultaneously flow the metal of the curved bottomradially outwardly of the cylindrical wall and then axially away fromthe curved bottom into a thickened annular rib extending radially andaxially away from its junction with the casing wall while at the sametime displacing the central area of the internal curved surface formingan internally located thickened button disposed at the central area ofthe curved bottom of the casing, and wiping said rib to form an annularskirt by radially inwardly displacing and axially downwardly elongatingthe rib thereby aligning the radial surface of the annular skirt withthe casing wall.

2. In a method of forming the curved bottom of a casing having acylindrical wall, the steps of backing up the periphery of the curvedsurface of the bottom from within the casing, pressing upwardly againstthe curved bottom from the exterior thereof while internally backing upthe periphery of the internal curved surface of the curved bottom andpressure relieving the centralarea of the curved surface therebydisplacing themetal of the curved bottom radially outwardly of thecylindrical wall and axially away from the curved bottom into athickened annular rib extending radially, and-axially away from itsjunction with the casing wall while at the same time displacing thecentral area of the internal curved surface forming an internallylocated thickened button disposed at the central area of the curvedbottom of the casing, and wiping said rib to form an annular skirt byradially inwardly displacing and axially outwardly elongating theannular rib concentrically aligning the radially outer surface of theannular rib with thecylindrical wall.

3. In an apparatus for forming the bottom of a casing having acylindrical wall, means including a plunger die member having acentrally recessed plunger forming head and a forming memberaboutsaidplunger die member having a flared lower wiping end with saidplunger die member movable with respect thereto for pressing longiwardthe flared end, said flared wiping end being movable over said noseportion for progressively elongating the obliquely inclined rib in anaxial direction to form it into an annular skirt depending downwardlyfrom the casing bottom in longitudinal alignment with the casing wall.

4. In an apparatus for forming the bottom of a casing having acylindrical wall, means including a plunger die memberhaving a centrallyrecessed forming head and a forming member about said plunger die memberhaving a flared lower wiping end with said plunger die member movablewith respect thereto for pressing longitudinally from within the casingagainst the inside surface of the bottom to displace metal radiallyoutwardly toward the flared lower end into a thickened bottom margin atits junction with the casing wall, and die means including a verticallymovable lower die member underlying the plunger die member having alower die member forming head of reduced diameter with respect to saidrecessed forming head, the lower die member forming head having aconcavely dished surface and an outer generally axial surface flaredaway from the plunger die member and delining with said concavely dishedsurface a metal displacing nose portion, one of said die members beingmovable relative to the other of the die members to lap the die membersthereby enabling the nose portion to displace the thickened marginbeyond the exterior confines of the easing wall toward the flared lowerend forming a thickened annular rib while the nose portioncontemporaneously directs the thickened margin obliquely toward theflared end, said flared lower wiping end portion and said nose portioncomprising means for progressively elongating said obliquely inclinedrib in anaxial direction to form it into an annular skirt depending awayfrom said casing bottom in longitudinal alignment with the casing wallby said portions being movable relative to each other.

5. In an apparatus for forming a bottom of a casing having a cylindricalwall, means including a plunger and a forming member about the plungerhaving a flared wiping portion with said plunger and said forming memberbeing movable with respect to one another, and die means including avertically movable lower die member underlying the plunger having aforming head of reduced diameter with respect to said plunger forco-action with 'the plunger and the flared portion of the formingmember,

said plunger being adapted to press longitudinally downwardly fromwithin the casing against the inside surface of the bottom while thebottom is backed up by the lower die member to displace metal from thebottom radially outwardly into a thickened bottom margin at its junctionwith the casing wall, said forming head of reduced dia- ..meter beingcooperable with the plunger in assisting in tudinally downwardlyfromiwithin, the casing against the inside surface of the bottom todisplace metal radially outwardly toward the flared lowerend into athickened bottom margin at its junction with the casing wall, and diemeans including a vertically movable lower die member underlying theplunger die memberhaving a forming head of reduced diameter with respectto said recessed A plunger forming head, the lower die member forminghead having a concavelydished head surface and an outer enerally axialsurface flared away from the plunger die menu her and defining with saidconcavely' dished'head surface a metal displacing nose, said lower diemember being movable! for pressing upwardly against the bottom from theexterior thereof with the nose portion displacing the thickened marginbeyond the-exteriorconfines of the casing walltoward the flared lowerend formingea thickened annula'r grib while the noseypoltioncontemporaneously directs the thickened margin obliquely downwardlytosaid obliquely inclined thickened annular rib in an axial direction toform it into an annular skirt of reduced cross sectional thicknessdepending downwardly from said casing'bottom' in longitudinal alignmentwith the casing wall. V

- References Qitcd in the file of this patent m UNITED STATES PATENTS

